Coupled-cluster theory for atoms and molecules in strong magnetic fields

摘要

An implementation of coupled-cluster (CC) theory to treat atoms and moleculesin finite magnetic fields is presented. The main challenges stem from themagnetic-field dependence in the Hamiltonian, or, more precisely, theappearance of the angular momentum operator, due to which the wave functionbecomes complex and which introduces a gauge-origin dependence. For thisreason, an implementation of a complex CC code is required together with theuse of gauge-including atomic orbitals to ensure gauge-origin independence.Results of coupled-cluster singles--doubles--perturbative-triples (CCSD(T))calculations are presented for atoms and molecules with a focus on thedependence of correlation and binding energies on the magnetic field.